What's up Doc? Incidentaloma somewhat common

Monday

Incidentaloma is a made-up word that refers to a benign tumor discovered incidentally, usually by some imaging exam such as CT or MRI. Dangers and treatments vary.

Q: When I was in the ER, I had a CT scan of my stomach to see if I had appendicitis. The good news was that I did not have appendicitis. The bad news was that they found a mass on my adrenal gland. They said it was probably nothing, but I had to get rechecked. What could this be?

A: You may be describing an adrenal "incidentaloma," so that is what I will discuss today. Be sure to follow your health-care provider's instructions for follow-up and to verify that this is what was found.

There is really no medical word "incidentaloma." This made-up word is from the word incidental with the suffix "oma" -- for a benign tumor -- added on. So this refers to a benign tumor discovered incidentally, usually by some imaging exam such as CT or MRI done for some other reason.

The question then becomes: Is the discovered mass truly benign and even if it is, does it do anything, such as secrete a hormone? I will focus my discussion today on adrenal incidentalomas, although incidentalomas can be found in other locations.

The adrenal gland is a small triangular-shaped organ that sits on top of the kidney and secretes hormones to regulate many things in the body.

It is actually pretty common to find a mass on the adrenal glands. Benign adrenal tumors are noted in 3 percent to 9 percent of autopsies, and are even more common in older patients and patients with a history of high blood pressure. Since 20 percent of these benign tumors secrete some hormone, the increased incidence of these in patients with high blood pressure is actually not surprising.

One large study done at the Mayo Clinic found masses on an adrenal gland (or both) in more than 3 percent of the 60,000 CTs they analyzed. Some of these CTs were ordered to look for cancer (or the spread of a known cancer) or to look for conditions that were suspected to involve the adrenal glands. Over half of the masses found were cancer, with another quarter of the masses being other identifiable lesions. About 17 percent were incidentalomas.

It is estimated that there are now more than 60 million CT scans done per year in the United States. With incidentalomas being pretty common and with this explosion of CTs (and MRIs) being ordered, there are more and more incidentalomas being identified.

Because of this, the National Institutes of Health convened an expert panel to determine what evaluation is required when an incidentaloma is discovered. Mass size (less than 4 centimeters), roundness, smoothness, density, speed that intravenous contrast ``washes out,'' unilateral nature and growth rate were all identified as characteristics that should be analyzed. Based on these characteristics this working group helped identify a set of criteria that defines a low risk (less than 1 in 1,000 to 10,000) of malignancy.

For masses that meet this low-risk criteria, the recommended workup includes blood and urine tests to determine if the mass is secreting hormones (as noted above, 20 percent of benign adrenal masses secrete some hormone), and a repeat imaging test in six months to see if, and how fast, it is growing.

For masses that secrete certain hormones, surgical removal is often recommended. Larger masses and masses that have characteristics suggesting they may be malignant (or at least that do not suggest they are benign), may also require an intervention. The specific surgery indicated (laproscopic versus open surgery) will depend on the specific characteristics of the mass.

Although many incidentalomas are lipomas (benign tumors made up of fat cells), losing weight will not shrink them as they are tumors and not just body fat.

If an incidentaloma is discovered, the necessary evaluation will depend on the details of the mass and other factors as discussed above. The appropriate treatment required should be discussed with your health care provider, noting that simple observation with no other intervention is a common recommendation for small, slowly growing, non-secreting, benign-appearing masses.